Gasoline prices popped back over $4 a gallon on Long Island over the weekend for the first time since March 7.
One expert forecast further increases due to an array of factors ranging from unrest in Egypt to unplanned refinery outages.
Regular gas averaged $4.005 a gallon in Nassau and Suffolk Monday morning, the AAA said. Prices have risen by 24.5 cents since the recent low point July 5.
The pump price increases come in the midst of the summer travel season, when demand for gasoline traditionally is the year's strongest.
Petroleum industry experts have attributed the rise largely to an increase in crude oil prices -- from $93.69 a barrel June 21 to almost $107 Monday for the U.S. benchmark grade -- on fears that political unrest following the Egyptian military's takeover of the government would cause disruptions of shipments through the Suez Canal, which Egypt controls and through which a significant amount of Middle East oil flows in tankers.
Stephen Schork, editor of the industry newsletter The Schork Report, said in Monday's edition that increased investment by Wall Street firms in crude and gasoline futures as alternatives to stocks were also factors pushing up prices.
Schork predicted that pump prices would rise further, even if crude prices don't, because this month's crude price increases haven't been passed through completely to consumers. "If we don't see a rapid correction [in crude prices], then we're looking at at least another 20-cent rise in prices by Labor Day," he said.
But another analyst, Andy Lipow, president of Houston consulting company Lipow Oil Associates LLC, thought pump prices might be close to peaking. He noted a decline Monday in gasoline futures of 6.83 cents to $3.06 a gallon wholesale on indications that a number of unplanned refinery unit shutdowns around the country and in Canada in recent weeks were being resolved. Bloomberg News, citing unnamed sources, reported Monday that Philadelphia Energy Solutions' facility in Philadelphia was operating normally again after a partial outage July 12. The complex is the largest on the East Coast.
Lipow expects problems to be resolved in coming weeks at another major supplier to this region, the Irving Oil refinery in St. John, New Brunswick, Canada.
"Overall, things are improving," he said.
U.S. crude oil fell $1.14 to $106.91 a barrel Monday on a disappointing report on home sales nationally, which raised concerns about the strength of the economy and future demand for petroleum.